Cationic methallylnickel(II) complexes with α-diimine ligands: synthesis and X-ray structure

The α-diimine ligands ArNC(R)C(R)NAr react with Ni(COD)2 (2) in the presence of methallyloxyphosphonium hexafluorophosphate [CH2C(Me)CH2OP(NMe2)3]+·PF6− (3) to give new cationic methallyl complexes of nickel(II) with α-diimine ligands 4a and 4b. The same complexes 4a–d can also be generated in high yields by reacting [α-diimine] NiBr2 with zinc and methallyloxyphosphonium salt 3. Molecular structure of 4a was determined by a single-crystal X-ray diffraction.